Electric switch gear



Nov. 25, 1930. A ALLAN ELECTRIC SWITCH GEAR Filed Jan. lOI 1950 3 Sheets-Sheet 2 New 25, i930. A ALLAN 1,782,594

ELECTRIC SWITCH GEAR Patented Nov. 25, 193() ELECTREC S'WETCH GEAR Application Afiled January it", i930, Serial No. f'l, and` in Great Britain February il, 19

This invention relates to electric switchgear, particularly to oil-in'lniersefl gear comgrising` a main circuit-breaker an( one or more isolating switches.

The object of the present invention is the construction ot oil-immersed gear ot this general type wherein a convenient and eliicient arrangement of' rotary isolating switch is employed.

ln switchgear according to this invention the isolatingl switch is actuated by a rotary member consisting of, or forming part of the casing` of, one of the conductors passing through the top plate or iixecl cover of the tanl; containing the main oil circuit-breaker and leading to the relatively ixecl contacts of the main circuit-breaker, the phrase relatively iixecl meaning in this connection the contacts which do not move in the ordinary opening' and closing movement of the main circuit-breaker.

Conveniently the conductor, which constitutes the rotary member or is enclosecl by a casing forming' that member, malice a draw-v out or plug ancl socket connection at its lower end with the relatively iixet main switch rontact, that contact itself being` heltl in an oil-tight cap at the bottom oi a hollow insulator which at itsY upper end is lixerl to the cover proper ot the main circuit-breaker oil tank, i. e. to the cover which moves flownvarrls with the circuit-breaker when it is lowered. The casing,` the conductor is preferably more or less spindle-shaped antl is formed at its upper and lower portions oi hollow insulators.

1When the conductor itself constitutes the rotary member the encls thereof pass through the hollow casing' insulators the bottoni end making a rotatable draw-out or plug and socket connection with the relatively iiXerl contact of the main circuit-breaker, whilst the upper end carries the blade of the isolatino; switch. In the alternative arrangement the hollow insulator surrounding` the upper part of the conductor constitutes the rotary member and has a concluctingxtop or cap which makes a rotatable connection, preferably also of the draw-out type, with the upper end of the conductor.

Thecasingisoil-lill i irougn an oil-iillecl hainbe i:- or carrieti h5.7 the top plate or tilted cover ot the Vthe circuit-breahel` and isolating s-.vitches7 Figure 2 is plan view, on an enlarge-rl scale7 of the isolating switch on the line 2 2 ot Figure l,

Figure 3 is a sectional leva-tion ot part of the circuit-breaker showing' au alterna tive arrangement ot isolating switch, and

Figure il is a view similar' to Figure 2 showing an isolating` switch 'for a duplicate busbar system.

Referring to Figures Il anil 2, an oil-iniinersecl switchgear arrangement i.-; liown in which a main circuit-breaker is irovitletl for connecting a bushar s vstein to a feeder. rEhe conductor il, which torins pai-t of or is connected to the bnshar svstein is leil into an oil-filled chamber B thrcngh an oil-tight insulator C carrying at its inner #ncl a contact C1. T iis contact cooperates with an isolating,l switch blatle l) i'ixorl on the upper encl of one terminal E oit the circuit-br il-er which projects into the chamber through an opening B1 in the bottom thereof. ji seconcl il-illecl chamber F, into which the othe terminal El ot the circuit-breaker projects in a similar manner, contains a sealing` insulator G for the feeder (not shown), a contact G1 on this insulator cooperating; with an isolating switch blade D1 iii-ed to the end of the terminal El.

The circuit-breaker main oil tank l has a cover lll to which it is attached by bolt:

tively. The relatively fixed contacts K and K1 of the circuit-breaker are mounted on oil-tight end caps L1 at the bottom of the hollow insulators L lixed at their upper ends to cylindrical chambers L2 which are tastened to the cover lL 1. The circuit-breaker operating mechanism "l which, since it forms no part of the present invention,

only illustrated diagrammatically, is also carried by the cover H1 and actuates a movable bridge piece K1 which, when the cirT cuit-breaker is Y in the closed position as shown in Figure l, connects the lixcd contacts K K1.

rThe terminal E of the circuit-breaker (shown in section in Figure l), which also forms the rotary member for the isolating switch D, has a central conductor N carrys ing at its lower end flexibly mounted Contact )locks N1. The contact blocks Nlfcooperate with a fixed contact K3 mounted within the end cap L1 and suitably rounded so as to Y form a connection of the draw-oidV orv plug and socket type and also to permit Lthe terminal E to be rotated. vThe vconductorV N is connected at its upper end by clamping nuts N2 to the isolating switch blade D and is contained in a spindle-shaped casing the lower partof'which is formed by a hollow insulator G inside the insulator L and ce-v mented as at 02 to the ring J. The upper portion of the spindle-shaped casing 1s formed by another hollow insulator O1 which projects into the chamber B. They to permit oil to dow from the main switch,

tank H into the chamber L2, the insulator L and the endv cap L1. The conductor N is also insulated inside the casing in any suitable manner, a condenser bushing insulator l? having a central liange P1 beingus-:ed in the arrangement showin The terminal E is supported by means ot a flanged ring Q, cemented at Q1 to the lower end of the insulator O1 and havinfy a machined surface Q2 whiclrrests on a corr-esponding machined surface B2 surrounding the opening B1Aoi the chamberB. The ring Q is held in position by means of an internally flanged ring B bolted to the chamber B, the two rings being so arranged as to permit rotation ol the terminal. The flange P1 of the insulator P is fixed to the lower side o1"- the ring- Q so that this insulator and the conductor N rotate with the casing insulator O1.

The terminal E is rotated and consequently the isolating switch D operated by means of a lever S carried on the end of a shaft S1 which projects through the top of the chamber B and is connected to the ring Q by link mechanism S2 (Figure 2). An earthbottom ofthe chamber B and a rotatable draw-out or plug and socket joint is provided byl means of the contact blocks N3 between the top of the conductor N and the cap di ot the insulator O1. The isolating` switch blade D is then carried by the cap O2 and is operated by rotating the hollow insulator Q1, the conductor N and its bushing` insulator bytbolts (not shown) Vto the underside of the Sil P remaining stationary. The flange P1 forms an oil-tight joint between the chamber B and the lower insulator Orso that, in the event of the insulator O being damaged, oil will not run from the chamber B into the switch tank. rThe lower insulator O is maintained full of oil by means of a by-pass connection U having a control cock U1 which connects t-hisF chamber to the chamber B. The control coclr U1 permits the by-pass to be closed when the main cover i-s lowered or during an emergency, as for example when the insulator O is fractured.

The connection between the top of the conductor N and the cap VO2 must necessarily be rotatable and is preferably'ot the draw-out type as shown to permit the conductor N and its insulator P to be withdrawn when the tank is lowered for inspection or renewal. ln or- Y der that this may be done without running the oil out of the chamber B an oil-tight oint is formed between the rings B- and Q by means ot the flange R1 on the. ringjR, the gland B3 and the packing l. In other respects tac constructionv of this alternative arrangement is similar to that shown in Figure l.

Tn lilgnr'e i an arrangement of the isolating switch tor a duplicate busbar system is shown, the isolating switch being used both for isolating` and for busbar selection. When the blade D2 in the positionfshown it acts purely as an isolating switch while, as'will be apparent from the four positions shown in cha in lines, it can be used to connect the circuitbreaker to either of the busbars A1, A2 or to either of the earth'ing contacts T1, T2.

lt' will be appreciated that this construction of circuit-breaker and isolating switch provides a simple and compact arrangement which enables the whole ot the cooperating current-carrying parts to be etciently oilinsulated and in which isolation can be obtained without lowering or withdrawingV the whole circuit-breaker as is usually necessary in drawout type switchgear. When the isolating switches are opened the circuitbreaker oil tanlralone can be lowered by open ing the. joint H2 and the contacts inspected or the whole circuit-breaker with its cover and operating mechanism can be lowered by opening the joint between the cover H1 and the rings ,l and J1, this latter operation being possible without disturbing in any way the terminal insulators or the isolating` switches. ln inultiphase switchgearthe circuit-breaker for each. phase may have isolating switches according to the inve tion and the operating` mechanisms tor the switches in the several phases may be linked together so that they can be ope ed by a single handle or by a common source ot power.

lu erlocking mechanism ot any suitable `form may be provided, tor instance, for preventing,l the operation ot the isolating' switches until the circuit has been broken by the main circuit-breal-er or when the tank or circuit-breaker is in the lowered position and for preventing' the lowering of the main circuit-bres. rer tank until the contacts of the isolatino; switches have themselves been isolated or earthed, but these details do not in themselves form part ot the present invention and the functions oli such interlocking` mechanism are well known.

lt will be appreciated that the above description is by way of example only and that many modifications may be made within the scope ot the invention. Thus for example although the rotary member has been described as carrying the blade oi the isolating; switch, obviously the blade might be fined and the rotary member might carry a series of contacts.

That I claim as my invention and desire to secure by Letters ljatent is l. Oil-immersed electric switchgear including' in combination a main oil tank, a cover lor the tank, a circuit-breaker in th tank, at least one terminal passing through the cover and leading to the circuit-breaker, an isolating switch mounted on the end o'i the terminal outside the tank, and means 'for rota ting at least a `part of the teri'ninal so as to ogerate the isolating' switch.

Oil-immersed el ctric switchgear including in combinationa main oil tank, a cover 'for the tank, a circuit-breaker 'in the tank, at least one hollen7 insulator fixed to the cover and projecting into the tank, an oil-tight cap at the bottom of the insulator, hired and movable contacts tor the circuitbreaker a lined Contact being Carried on the can, a terminal passing through the cover into the hollow insulator, a draw-out connection between the lower end of the terminal andthe fined Contact on the cap, an isolating switch mounted on the upper end of the terminal outside the tank, and means for rotating' at least a part oi the terminal so as to operate the isolating' switch.

A3. Oil-immersed electric switchgcar including` in combination a main oil tank, a cover for the tank, a. circuit-breaker in the tank,

at least one hollow insulator i'iXed to the cover and projecting into the tank, an oil-tight cap at the bottom of the insulator, Xed and movable contactsV for the circuit-breaker a fixed Contact being` carried on the cap, a conductor, a casing for the conductor, hollow casing insulators forming the ends or" the casing, the conductor and casing passing through the cover of the tank so that the lower casing; insulator is surrounded by the hollow insulator, a draw-out connection between the lower end oiu the conductor and the lined Contact on the cap, an isolatingswitch blade mounted on the end ot the upper casing insulator', a connection between the ugper end el the conductor and the switch blade, and means :for rotating` at least a part o'l the terminal so as to operate the isolating` switch blade.

l. Oil-immersed electric switchgear including in combination a main oil tank, a cover for the tank, a circuit-breaker in the tank, at least one oil-filled chamber lined to the inner side of the cover, a hollow insulator mounted on the lower end of the chamber, an oil-tight cap at the bottom oir the insulator, fined and movable contacts for the circuitbreaker a fixed contact being carried on the can, conductor, a casing,` for the conductor, hollow casing` insulators forming ends ot the casing, the conductor and casingpassing through the covery of the tank and the oillilled chamber so that the lower casing` insulator is surrounded by the hollow insulator, a draw-out connection between the lower end of the conductor and the lined contacton the cap, an isolatino switch blade mounted on the end of the upper casing insulator, a connection between the upper end ot the conductor and the switch blade, and means for rotating atleast a part ot' the terminal so as to operate the isolating switch blade.

5. ln oil-immersed electric. cmnbiimtion oli' the task, a circuit-br( one conductor passing leading to the circuithe conductor, ho l i in?,` the ends oft means for supporting the upper .u .atoronthc utside oi the cover, an isolating switcblade carried by the upper casing' insulator, a connection beti Ye. i the end of theconductor and the switch blade, and means for rotating the upper casing insulator so as to operate the switch blade.

6. Ln oil-immersed electric switchgear the combination oi a. main oil tank a cover for sfilcl'igar "he rank, a cover 1 rinthelaulnatle h me cover a r, a casing; 1

ulators torinin the tank, at l' throu" i the cove CIJ carried by the upper casing insulator, a roblade, andmeans tor rotating the upper casing,` insulator so as to operate the switch blade.

ln oil-immersed elect ic switcligear the Combina ion ot a main oil tank, a Cover for the tank, a circuit-breaker in the tank, at least one Conductor passing through the cover and leading to the circuit=breal';er, a easing for the conductor, hollow casinginsulators torining the ends ofthe casing, means for supporting the upper easing insulator on the outside of the cover, an oiltigl1t joint between the lower end ot the upper casing insulatorV and the cover which permits rotation ot the insulator, an isolating switch blade carried by the upper casing insulator, a rotatable draw-out connection between the upper end of the conductor andthe switch blade, and means or rotating the upper casing insulator so as to operate the switch blade.

S. Y Oil-immersed electric switehgear cluding' in combination a main oil tank, a cover tor the tank, a circuit-breaker in tank, at least one hollow insulator fixed to the inner side of the cover, an oil.-tiglit cap at v the bottom ofthe insulator, lined and movable contacts 'for the Circuit-breaker a i'ixed contact being,` carried on the Cap, at least one insulatedv conductor passing through the 4@over into the hollow insulator, a casing for the Qoni ductor, hollow easing insulators'torming the ends of the'casing, an oil-tight oint bet veen the lower end of the upper casing insulator and th-e outside of the Cover which permits rotation'ot the insulator, a draw-out connection between the lower end of the conductor and the iXed contact in the cap, an isolating switch blade carried by the upper casing insulator, a rotatable draw-out connection between the upper end ot the conductor andl the switch blade, and means for rotating the upper casing insulator sous to ope-"fattl isolating switch blade.

'9. Oil-immersed electric switchgear including;- in combination alinain oil tank. a

cover tor the tank, a circuit-breaker in the tank, at least one hollow insulator lined lo the'inner sideot the cover, an-oil-tight cap at the bottom ot the insulatonxed and morable oontacts tor the circuit-breaker a. lined Contact being carried on the cap, at least one insulated conductor passing through the cover into the hollow insulator, a easing tor the eonduoto-r, hollow casing insulators forniing the ends of the casing', an oil-tight joint between the lower end ot' the upper casing; insulator andtheA outside ofthe cover which permits rotation of the insulator, an oil-filled Chamber surrounding the upper casing insulator, a draw-out connection between the lower end of the conductor and thetixed oon-'- taetin the cap, an isolating" switch bla-de carried by the upper casing insulator,.cooperat connection between the upper end of the conductor and theswitch blade, and means for rotating` the upper casing. insulator so asy to- ARCHIBALD ALLAN.

ingv Contacts for the switch blade supported inthe oil-filled Chamber, a rotatable draw-out 

